Surface treatment method for metal housing

ABSTRACT

A surface treatment method for a metal housing includes: providing a metal housing made of an oxidizable alloy; performing a surface treatment on the metal housing, to obtain a semi-finished housing, the surface treatment comprises at least one selected from the group consisting of a micro-arc oxidation treatment, a surface painting treatment, a surface cutting treatment, a surface drawing treatment, and a surface defect treatment, the semi-finished housing comprising a substrate-exposed region; and performing a filming treatment on the semi-finished housing, to passivate the substrate-exposed region.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of U.S. Provisional Application Ser. No. 62/900,698, filed on Sep. 16, 2019 and China Application Serial No. 202010722542.5, filed on Jul. 24, 2020. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of the specification.

BACKGROUND OF THE INVENTION Field of the Invention

The disclosure relates to a housing manufacturing method, and in particular, to a surface treatment method for a metal housing.

Description of the Related Art

In a process of manufacturing a conventional metal housing, a metal substrate is usually polished first and then treated by computer numerical control (CNC). However, a region treated by CNC is prone to oxidation. To resolve the problem of oxidation, in some methods, a region treated by CNC is coated by physical vapor deposition (PVD) or electroplating. However, these methods result poor anti-oxidation effects. In some other methods, a micro-arc oxidation treatment is performed in a region treated by CNC. However, the treatment causes the metal luster lost, adversely affecting the appearance presentation of the metal housing.

BRIEF SUMMARY OF THE INVENTION

The disclosure provides a surface treatment method for a metal housing. The method includes steps of: providing a metal housing made of an oxidizable alloy; performing a surface treatment on the metal housing, to obtain a semi-finished housing, the surface treatment comprises at least one selected from the group consisting of a micro-arc oxidation treatment, a surface painting treatment, a surface cutting treatment, a surface drawing treatment, and a surface defect treatment, the semi-finished housing comprising a substrate-exposed region; and performing a filming treatment on the semi-finished housing, to passivate the substrate-exposed region.

By means of the surface treatment method for a metal housing provided in the disclosure, the oxidation problem in the process of manufacturing a metal housing is effectively controlled, and the metallicity of a housing substrate is maintained, thereby enhancing the appearance presentation of the metal housing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flowchart of an embodiment of a surface treatment method for a metal housing according to the disclosure; and

FIG. 2 is a flowchart of another embodiment of a surface treatment method for a metal housing according to the disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

More detailed descriptions of the embodiments of the disclosure are provided below with reference to the accompanying drawings. The features and advantages of the disclosure are described more clearly according to the following description and claims. It is to be noted that all of the drawings use very simplified forms and imprecise proportions, only being used for assisting in conveniently and clearly explaining the objective of the embodiments of the disclosure.

FIG. 1 is a flowchart of an embodiment of a surface treatment method for a metal housing according to the disclosure.

First, as shown in step S120, a metal housing is provided. The metal housing is made of an oxidizable metal. In an embodiment, the oxidizable metal is a magnesium alloy (in an embodiment, magnesium alloy AZ91D) or an aluminum alloy.

Next, as shown in step S140, a micro-arc oxidation treatment is performed on the metal housing. In an embodiment, apart from performing the micro-arc oxidation treatment on the metal housing, a filming treatment is also performed in the foregoing step S140, to improve the anti-oxidation effect.

Subsequently, as shown in step S150, a surface painting treatment is performed on the metal housing obtained after the micro-arc oxidation treatment in step S140, to present a preset color or luster.

Next, as shown in step S160, a surface cutting treatment is performed on a semi-finished metal housing that obtained from the surface painting treatment in step S150. The semi-finished housing includes a substrate-exposed region. In an embodiment, the surface cutting treatment is an edge cutting treatment, but is not limited thereto. Alternatively, in an embodiment, the surface cutting treatment is to perform a cutting treatment on a flat surface of the metal housing according to a preset pattern (in an embodiment, a logo), to produce a substrate-exposed region.

Subsequently, as shown in step S180, a filming treatment is performed on the semi-finished housing produced by using a surface treatment in the foregoing steps S140 to S160, to passivate the foregoing substrate-exposed region, reduce the oxidation in the substrate-exposed region, and provide an anti-oxidation effect to a particular extent.

In an embodiment, an electrical film formation step is used in the foregoing filming treatment, to form a film layer on the surface (especially in the substrate-exposed region) of the semi-finished housing. Parameters of the electrical film formation step are as follows: the pH value of a treatment environment is 7 to 10; the voltage is 3 V to 10 V; and the treatment time is 0.5 minutes to 2 minutes.

In an embodiment, an electrical film formation step and a heating film formation step are used in the foregoing filming treatment, to form a film layer on the surface of the semi-finished housing. Parameters of the electrical film formation step are as described above. Parameters of the heating film formation step are as follows: the pH value of a treatment environment is 5 to 7; the treatment temperature is 40° C. to 50° C.; and the treatment time is 1 minute to 3 minutes. In an embodiment, an eco-friendly filming agent such as a non-phosphate filming agent or a non-chromate filming agent is used in the foregoing filming treatment.

Finally, as shown in step S190, an anodic electrodeposition treatment is performed on the semi-finished housing obtained after the filming treatment in step S180. In an embodiment, parameters of the anodic electrodeposition treatment are as follows: the pH value of a treatment environment is 4 to 6; the voltage is 70 V to 150 V; and the treatment time is 20 seconds to 70 seconds. The anodic electrodeposition treatment is mainly performed on the substrate-exposed region of the semi-finished housing, colors the substrate-exposed region to produce metallicity, and provides the anti-oxidation effect. In an embodiment, the anodic electrodeposition treatment is a matte anodizing treatment or a high-gloss anodizing treatment, to meet different requirements.

FIG. 2 is a flowchart of another embodiment of a surface treatment method for a metal housing according to the disclosure.

First, as shown in step S220, a metal housing is provided. The metal housing is made of an oxidizable metal. In an embodiment, the oxidizable metal is a magnesium alloy or an aluminum alloy.

Next, as shown in step S240, a surface defect treatment is performed on the metal housing, to remove defects produced during the formation of the metal housing, so that the surface is flat and glossy. In an embodiment, apart from performing the surface defect treatment on the metal housing, an electro polishing treatment is also performed in the foregoing step S240, to further improve the surface finish.

Next, as shown in step S260, a surface drawing treatment is performed on the metal housing obtained after the surface defect treatment in step S240, to produce a semi-finished housing. The surface of the semi-finished housing presents drawing metallicity. After the foregoing surface drawing treatment, the semi-finished housing includes at least one substrate-exposed region.

Subsequently, as shown in step S280, a filming treatment is performed on the semi-finished housing obtained after the surface treatment in the foregoing steps S240 and S260, to passivate the foregoing substrate-exposed region, reduce the oxidation in the substrate-exposed region, and provide an anti-oxidation effect to a particular extent. Step S280 is similar to step S180 in FIG. 1. Details are not described herein.

Finally, as shown in step S290, an anodic electrodeposition treatment is performed on the semi-finished housing that obtained from the filming treatment in step S280. Step S290 is similar to step S190 in FIG. 1. Details are not described herein.

In summary, the surface treatment method for a metal housing provided in the disclosure is to perform a surface treatment on a metal housing, to provide the semi-finished housing with a substrate-exposed region; and then performing a filming treatment on the semi-finished housing. The surface treatment is not limited to the treatment procedure described in step S140 to step S160 in FIG. 1 and step S240 to step S260 in FIG. 2 in the disclosure. According to actual requirements, the surface treatment includes at least one selected from the group consisting of a micro-arc oxidation treatment, a surface painting treatment, a surface cutting treatment, a surface drawing treatment, and a surface defect treatment, and all of the surface treatments produce a substrate-exposed region on the metal housing.

In addition, in the surface treatment method for a metal housing shown in FIG. 1 and FIG. 2, an anodic electrodeposition treatment is performed on the semi-finished housing obtained from the filming treatment in step S180 and step S280 (that is, step S190 and step S290). However, the disclosure is not limited thereto. According to actual requirements for the surface appearance effect, the step of the anodic electrodeposition treatment is alternatively omitted, or the step is replaced with another surface coating step such as a cathodic electrodeposition treatment.

According to the surface treatment method for a metal housing provided in the disclosure, the oxidation problem while manufacturing a metal housing is effectively controlled, and the metallicity of a housing substrate is maintained, thereby enhancing the appearance presentation of the metal housing.

Although the disclosure is described with reference to the above embodiments, the embodiments are not intended to limit the disclosure. A person of ordinary skill in the art may make variations and modifications without departing from the spirit and scope of the disclosure. Therefore, the protection scope of the disclosure should be subject to the appended claims. 

What is claimed is:
 1. A surface treatment method for a metal housing, comprising: providing a metal housing made of an oxidizable alloy; performing a surface treatment on the metal housing, to obtain a semi-finished housing, the surface treatment comprising at least one selected from the group consisting of a micro-arc oxidation treatment, a surface painting treatment, a surface cutting treatment, a surface drawing treatment, and a surface defect treatment, the semi-finished housing comprising a substrate-exposed region; and performing a filming treatment on the semi-finished housing, to passivate the substrate-exposed region.
 2. The surface treatment method for a metal housing according to claim 1, further comprising: performing an anodic electrodeposition treatment on the semi-finished housing, the pH value of a treatment environment of the anodic electrodeposition treatment is 4 to
 6. 3. The surface treatment method for a metal housing according to claim 1, wherein the oxidizable alloy is a magnesium alloy or an aluminum alloy.
 4. The surface treatment method for a metal housing according to claim 1, wherein the surface treatment comprises the micro-arc oxidation treatment, the surface painting treatment, and the surface cutting treatment.
 5. The surface treatment method for a metal housing according to claim 4, wherein the surface cutting treatment is an edge cutting treatment.
 6. The surface treatment method for a metal housing according to claim 1, wherein the surface treatment comprises the surface defect treatment and the surface drawing treatment.
 7. The surface treatment method for a metal housing according to claim 1, wherein the filming treatment comprises an electrical film formation step.
 8. The surface treatment method for a metal housing according to claim 7, wherein the pH value of a treatment environment of the electrical film formation step is 7 to
 10. 9. The surface treatment method for a metal housing according to claim 7, wherein the filming treatment comprises the electrical film formation step and a heating film formation step.
 10. The surface treatment method for a metal housing according to claim 9, wherein the pH value of a treatment environment of the heating film formation step is 5 to
 7. 11. The surface treatment method for a metal housing according to claim 1, wherein the filming treatment is performed by using a non-phosphate filming agent or a non-chromate filming agent. 